Refractory closure member for bottom pour vessels



4 Sheets-Sheet 1 Nov; 14, 1967 J. T. SHAPLAND REFRACTORY CLOSURE MEMBERFOR BOTTOM POUR VESSELS File May 6, 1965 FIG.

Nov. 14, 1967 J. T. SHAPLAND REFRACTORY CLOSURE MEMBER FOR BOTTOM POURVESSELS 4 Sheets-Sheet 2 Filed May 6, 1965 INVENTOR JAMES T. SHAPLANDMfi 031% ATTORNEY Nov. 14, 1967 J. T. SHAPLAND 3,352,465

REFRACTORY CLOSURE MEMBER FOR BOTTOM POUR VESSELS Filed May 6, 1965 4Sheets-Sheet 5 INVENTOR JAMES T. SVHAPLAND ATTORNEY Nov. 14, 1967 J. T.SHAPLAND 3,352,465

REFRACTORY CLCSURE.MEMBER BOTTOM POUR VESSELS Filed May 6, 1965 4Sheets-Sheet 4 FIG .8

' INVENTOR JAMES T- SHAPLAND ATTORNEY United States Patent 3,352,465REFRACTORY CLOSURE MEMBER FOR BOTTOM POUR VESSELS James T. Shapland,Churchill, Pa., assignor to United States Steel Corporation, acorporation of Delaware Filed May 6, 1965, Ser. No. 453,730 5 Claims.(Cl. 222-512) ABSTRACT OF 7 THE DISCLOSURE Flanges at the sides of theblock ride on the rails. A.

hole through the block is brought in register with the outlet by afluid-pressure cylinder.

This invention relates to bottom pour vessels adapted for use in thecontinuous casting of steel, and more pa.r ticularly to means forcontrolling the rate of discharge of the molten steel from such vessels.

Stopper rods such as those commonly used on bottom pour ladles are notsuitable for either tundishes or vacuum degassing vessels for severalreasons. First of all, it is desirable in continuous casting tointroduce molten steel into the mold over long periods of time, andindefinitely if possible. Stopper rods and bottom pour nozzles have ashort life, frequently one hour or less, in the presence of moltensteel. This necessitates taking the vessel offstream whenever it isnecessary to replace either the nozzle or the stopper rod. Furthermore,a stopper rod is not suited for use in a degassing vessel, because thestopper rod and associated mechanism for its operation are locatedpartly inside and partly outside the vessel, requiring a vacuum tightseal.

Summary of the invention The apparatus of this invention includes abottom pour vessel having a discharge nozzle in the bottom wall thereofand means for controlling the discharge of molten steel through saidnozzle comprising a slidable refractory closure member, means forsliding the closure member into and out of nozzle closing position, andmeans for holding the closure member against the exterior end of thenozzle. According to one embodiment of this invention, the closuremember is a slidable refractory block having an imperforate portion anda teeming opening for closing and opening the nozzle, respectively.According to another embodiment, the closure member comprises aplurality of separate refractory plates including an imperforate platefor closing the discharge nozzle and a plate having a teeming openingfor controlled discharge of steel.

Brief description 0 the drawings FIG, 6 is a sectional view taken alongline 66 of FIG. 4.

3,352,465 Patented Nov. 14, 1967 FIG. 7 is a sectional view of a detailtaken along line 77 of FIG. 4.

FIG. 8 is an elevational view of a vessel having the closure device ofthis invention mounted on the exterior thereof shown in a position abovea continuous casting mold.

Description of preferred embodiment Referring now to FIGS. 1 to 3, 10 isa refractory lined bottom pour vessel, such as a degassing vessel ortundish, which is adapted to contain molten steel. Vessel 10 has abottom wall 11 which has a nozzle 12 for the discharge of molten steelfrom the vessel. Nozzle 12 is a sleeve shaped member, defining acylindrical bore 13 and hav ing a flat exterior end 14 which is adaptedto receive a refractory closure member in sliding contact. Because ofthe extreme amount of wear to which nozzle 12 is subjected, it isdesirable to make this nozzle of a refractory which is more resistant toerosion than the refractory which lines the interior of vessel 10.

Vessel 10 in the embodiment of FIGS. 1-3 includes means for controllingthe discharge of molten steel through nozzle 12 comprising a slidablerefractory closure member 15 mounted on the exterior of vessel 10.Closure member 15 is movable between nozzle-opening position, in whichsteel is discharged at a controlled rate from vessel 10, andnozzle-closing position in which the discharge of molten steel fromvessel 10 is prevented. Closure member 15 is in the shape of arectangular block or panel 15 having a flat upper surface 16 which isadapted to make sliding contact with the exterior end surface 14 ofnozzle 12. Refractory block 15 includes a tubular nozzle insert 17defining a restricted opening 18 for teeming of molten steel, a secondopening 19 which is of the same diameter as the bore of nozzle 13 forpreheating the vessel, and an imperforate central portion 20 locatedbetween teeming opening 18 and large opening 19 for closing of nozzle 12so as to prevent discharge of molten steel'from vessel 10. Nozzle insert17 is preferably made of a refractory which is more resistant to erosionthan the refractory material of which the'remainder of closure member 15is made. Opening 19 of large diameter is used only when vessel 10 isempty, and serves primarily to permit preheating of vessel 10. L-shapedangles 21 are provided along the outer edges-of closure member 15 aroundthe entire perimeter thereof in order to provide support for and preventchipping of the edges. A plurality of metal flanges 22, welded to angles21 and extending outwardly therefrom provide contact surfaces forengagement by supporting members which hold closure member 15 in contactwith the exterior end 14 of nozzle 12, as will be hereinafter described.

Sliding movement of closure member 15 means of a fluid pressure cylinder26, which is supported by trunnions 27 on U-shaped bracket 28, which inturn is afllxed to mounting bracket or flange 29 secured to the side ofvessel 10. Cylinder 26 has a piston rod 30 extending therefrom in onedirection. This piston rod 30 teris eifected by minates in a yoke 31which is secured by pin 32 to tongue 33, which in turn is welded toangle member 21. The admission of fluid under pressure to one side orthe other of cylinder 26 eflFects reciprocating movement of refractoryclosure member 15 between nozzle-opening position, in which teemingopening 18 is aligned with nozzle bore 13, and nozzle-closing position,in which the imperforate central portion 20 of closure member 15prevents flow of steel through nozzle bore 13. Opening 19 in closuremember 15 is not placed in alignment with the discharge opening 13 ofvessel 10 except when the vessel is empty, as previously indicated.Appropriate limit stop means to be hereinafter described prevent the ac-I cidental movement of refractory block 15 to the position in whichopening 19 is aligned with discharge opening 13.

A metal plate 40 of generally rectangular cross section is afiixed tothe exterior side of the bottom Wall of vessel by means of screws 41.This plate 40 carries the structure 42 which holds refractory blockagainst the exterior end 14 of nozzle 12. This support structure 42includes a plurality of spring loaded levers 43 on either side of nozzle12. Levers 43 are pivotally mounted near their centers on a pair oflongitudinally extending rods 44, one on either side of nozzle 12. Rods44 are supported from plate 40 by means of tongues 45. The outer ends oflevers 43 are urged downwardly by compression springs 47. This causesthe inner ends of levers 43 to press upwardly against lugs 22, therebyholding refractory closure member 15 in fluid-tight engagement againstthe lower end 14 of nozzle 12.

Compression springs 47 are located between plate 40 and retainer plates48, urging the latter downwardly. The compressive force of springs 47 istransmitted to levers 43 through set screws 49, which are received inscrew-threaded sockets in levers 43 and which terminate at their upperends in ball joints 50 mounted in swivel sockets 51 on retainer plates48, providing operative connections between springs 47 and levers 43.The compressive force exerted by springs 47 can be regulated byadjustment of the positions of set screws 49. Levers 43 have recesses 52at their inner ends for receiving metal rods 53 which preferably extendlongitudinally. One of these rods 53 is located on either side of nozzle12. Metal rods 53 are welded to bars or rails 54 positioned below lug 22and having upstanding flanges along both sides. A pad 55 of graphite orother suitable lubricating material is preferably interposed between bar54 and flange 22.

Movement of sliding refractory closure member 15 to a position placingopening 19 in alignment with nozzle opening 13 is prevented by means ofa limit stop which is constituted by a laterally extending rod 56supported at each end by lugs 57 depending from plate 40. In order toslide closure member 15 to the position in which opening 19 is alignedwith nozzle bore 13, rod 56 is first removed. Admission of fluid tocylinder 26, instead of moving refractory closure member 15 tonozzle-closure position, will then cause the closure member 15 tocontinue to move until larger diameter opening 19 is aligned with nozzlebore 13.

In the operation of the device illustrated in FIGS. 1 to 3, closuremember 15 is moved to nozzle-closing position by appropriate actuationof cylinder 26 before any molten steel is poured into vessel 10. Moltensteel is then poured into vessel 10. The nozzle opening 13 is thenplaced over the receptacle which is to receive molten steel, as forexample a continuous casting mold. Closure member 15 is then moved tonozzle-opening position, in which opening 18 is aligned with nozzleopening 13, by appropriate actuation of cylinder 26. When it is desiredto cut off flow of molten steel from vessel 12, refractory closuremember 15 is again moved to nozzle-closing position as shown in FIG. 2.Limit stop 56 prevents accidental alignment of large diameter opening 19with nozzle opening 13.

The closure member 15 provides a fluid-tight closure for vessel 10, andis therefore particularly well suited for use on vacuum degassingvessels. This closure member is free from operating difliculties due tofreezing steel, since the sliding movement of the closure memberprevents accumulation of molten steel between the closure memher and theexterior end 14 of nozzle 12. The exterior location of closure member 15permits rapid replacement, minimizing the length of time the vessel 10is out of service for such replacement.

Description of modification The modification illustrated in FIGS. 4 to 7permits replacement of worn flow-control and closure members withoutshutdown of the vessel. This modification also makes it possible to teemmolten steel at different rates. The means for controlling the dischargeof molten steel comprises a plurality of separate refractory plates,including an imperforate closure plate 60 and a flow-control plate 61having a teeming opening 62 therein. Both plates 60 and 61 are flatsquare or rectangular plates having guide ways 61a along their loweroutside edges. Means are provided for sliding these refractory platessucces-' sively into and out of position beneath nozzle 12 so asalternately to open and close discharge opening 13. A plurality offlow-control plate-s 61 having teeming openings 62 of differentdiameters permits control of the discharge rate of molten steel fromvessel 10. The structure of bottom-pour vessel 10, which has arefractory-lined outer wall structure'including a bottom wall 11 havinga nozzle 12 therein, may be identical to that described in connectionwith FIGS. 1 to 3.

Refractory plates 60 and 61 are moved in a linear path into and out ofposition beneath nozzle opening 13 by means of a fluid pressure cylinder26 and pusher 63.

Cylinder 26 has a piston rod 30 which terminates in tongue 31. Pusher 63extends the entire width of plates 60 and 61 and is secured to tongue 31by pin 64. This pusher 63 is adapted to contact the edge of refractoryplate 60 or 61 and to push a series of such plates in edge-to-edgeengagement in a linear path away from cylinder 26. A pair of guides 65extending parallel to the axis of cylinder 26 are provided for guidingthe movements of refractory plates 60 and 61 into and out of engagementwith the exterior end 14 of nozzle 12. These guides include graphitebars 67 and metal supporting bars or rails 66, both of rectangular crosssection. Supporting bars 66 are welded to rods 53 to prevent lateralmovement.

At least one imperforate plate 60 and one plate 61 having a teemingopening are placed on guides 65. Pusher 63 contacts an edge of one ofthese plates, pushing both plates in edge-to-edge engagement alongguides 65 away from cylinder 26. Nozzle opening 13 is alternately openedand closed by placing first a flow control plate761 and then animperforate plate 62 in contact with the exterior end 14 of nozzle 12.For convenience a plurality of imperforate plates 60 and flow-controlplates 61 may be placed in alternating sequence on guides 65. Twosuccessive flow-control plates 61 may also be placed on guides 65, asfor example when an eroded flow-control plate 61 is being replaced; Atable of 68a having a pair of laterally extending guides 68 provides aconvenient means for placing refractory plates 60 and 61 onlongitudinally extending guides 65 in a position Where they may becontacted by pusher 63.

The structure 42 for maintaining refractory plates 60 and'61 in contactwith the exterior end 14 of nozzle 12 is the same as the correspondingstructure 42 illustrated in FIGS. 1 to 3.

The device of FIGS. 4 to 7- permits changing of Howcontrol plates 61Without interruption of use of vessel 10. When a plate 61 becomes erodedand is no longer useful, or in the event opening 62 becomes partlyobstructed by skull or non-metallic inclusions, the defective plate 61is moved out of the way and a new plate 61 substituted in its place bysliding the plates along guides 65.

In operation according to FIGS. 4 to 7, a vessel 10 is positioned sothat nozzle 12 is directly above a receptacle, such as acontinuous-casting mold, which is to receive steel from the vessel.During start-up of the apparatus, an imperforate closure plate 60 isplaced over nozzle opening 13 to prevent discharge of steel until vessel10 is filled to the desired operating level. A uniform operating levelin vessel 10 is desirable in order to maintain a constant dischargerate. Imperforate refractory plate 60 is pushed out of position beneathnozzle 12 and flowcontrol plate 61 having a teeming opening 62 is pushedinto position by pusher 60 to initiate pouring. To stop pouring, plate61 is pushed out of position and an imperforate plate 60 is pushed intoposition by pusher 63.

The structure of FIGS. 4 to 7 readily permits controlling of teemingrates, simply by use of a plurality of plates 61 having openings 62 ofdifferent diameters.

Referring now to FIG. 8, a bottom pour vessel 10 having a closure deviceas illustrated in FIGS. 4 to 7 is positioned so that the dischargenozzle 12 is directly above a vertical tubular open-ended Water-cooledcontinuous-casting mold 70. The nozzle 12 is closed by means of animperforate refractory plate until it is desired to pour molten steelinto mold 70. Then cylinder 26 is actuated so as to push refractoryplate 60 out of the way and push a flow-control refractory plate 61having a teeming opening therein into position beneath nozzle 70. Thispermits teeming of molten steel into the mold 70 at a controlled rate.The teeming rate depends on the diameter of the teeming opening 62 inrefractory plate 61. When the teeming opening in refractory plate 61becomes enlarged due to erosion, a second refractory plate 61 issubstituted therefor simply by pushing the old plate 61 out of the wayand pushing the new plate 61 into its place. To cut off the flow ofmolten steel, an imperforate plate 60 is pushed into position beneathnozzle 12 in place of the refractory plate 61 having a teeming opening.

Vessel 10 has been illustrated as a vacuum degassing vessel in FIG. 8.Of course, vessel 10 may be any type of vessel suitable for containingmolten steel, as for example a tundish. Although the present inventionhas been described with particular reference to apparatus for handlingmolten steel, it will be understood that the invention is applicable tohigh-temperature apparatus for handling other molten metals.

While FIG. 8 illustrates a closure device for the embodiment shown inFIGS. 4 t 7, it will be understood 35 that the closure device shown inFIGS. 1 to 3 may be provided on the exterior of vessel 10 instead.

What is claimed is:

1. In a bottom-pour vessel for teeming steel, having a 4 nozzle in thebottom thereof and a panel slidable on said bottom to control flowthrough said nozzle, the improvement comprising a row of levers of thefirst class pivotedly attached to the bottom of said vessel on each sideof said panel normal to the path thereof, a rail on each side of saidpanel parallel to said path engaged and supported by the inner ends ofthe adjacent levers, a bearing surface on each side of said panelengaged and supported by the adjacent rail, and means urging the outerend of each lever downward.

10 2. An apparatus as defined in claim 1, characterized by pivot bearingmeans between said rails and levers permitting tilting of the rails onaxes parallel to the path of said panel.

5. An apparatus as defined in claim 1, characterized by said bearingsurface being a flange projecting laterally from the panel.

References Cited UNITED STATES PATENTS 311,902 2/ 1885 Lewis 222-5 05977,271 11/ 1910 Callaghan 2225 12 1,160,775 11/1915 Shearer 267172,921,351 l/1960 Momm 25111 3,259,946 7/ 196 6 Blue l64344 FOREIGNPATENTS 1,155,082 4/ 1958 France.

25,182 8/ 1898 Great Britain. 61 1,024 10/ 1960 Italy.

J. SPENCER OVERHOLSER, Primary Examiner.

0 R. D. BALDWIN, Assistant Examiner.

1. IN A BOTTOM-POUR VESSEL FOR TEEMING STEEL, HAVING A NOZZLE IN THEBOTTOM THEREOF AND A PANEL SLIDABLE ON SAID BOTTOM TO CONTROL FLOWTHROUGH SAID NOZZLE, THE IMPROVEMENT COMPRISING A ROW OF LEVERS OF THEFIRST CLASS PIVOTALLY ATTACHED TO THE BOTTOM OF SAID VESSEL ON EACH SIDEOF SAID PANEL NORMAL TO THE PATH THEREOF, A RAIL ON EACH SIDE OF SAIDPANEL PARALLEL TO SAID PATH ENGAGED AND SUPPORTED BY THE INNER ENDS OFTHE ADJACENT LEVERS, A BEARING SURFACE ON EACH SIDE OF SAID PANELENGAGED AND SUPPORTED BY THE ADJACENT RAIL, AND MEANS URGING THE OUTEREND OF EACH LEVER DOWNWARD.